package com.ljq.cksp.security.filter;

import com.ljq.cksp.util.JWTUtil;
import org.springframework.security.authentication.AuthenticationManager;
import org.springframework.security.authentication.UsernamePasswordAuthenticationToken;
import org.springframework.security.core.authority.SimpleGrantedAuthority;
import org.springframework.security.core.context.SecurityContextHolder;
import org.springframework.security.web.authentication.www.BasicAuthenticationFilter;

import javax.servlet.FilterChain;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.util.Collections;


/**
 * @Author:ljq
 * @Date:2020/4/23
 */
public class JWTAuthenticationFilter extends BasicAuthenticationFilter{

    public JWTAuthenticationFilter(AuthenticationManager authenticationManager) {
        super(authenticationManager);
    }

    @Override
    protected void doFilterInternal(HttpServletRequest request, HttpServletResponse response, FilterChain chain)
            throws IOException, ServletException {
        String tokenHeader = request.getHeader(JWTUtil.TOKEN_HEADER);
        // 如果请求头中没有Authorization信息则直接放行了
        if (tokenHeader == null || !tokenHeader.startsWith(JWTUtil.TOKEN_PREFIX)) {
            chain.doFilter(request, response);
            return;
        }
        // 如果请求头中有token，则进行解析，并且设置认证信息
        SecurityContextHolder.getContext().setAuthentication(getAuthentication(tokenHeader));
        super.doFilterInternal(request, response, chain);
    }

    private UsernamePasswordAuthenticationToken getAuthentication(String tokenHeader) {
        String token = tokenHeader.replace(JWTUtil.TOKEN_PREFIX, "");
        String id = JWTUtil.getId(token);
        String role = JWTUtil.getUserRole(token);
        System.out.println(role);
        if (id != null){
            return new UsernamePasswordAuthenticationToken(id, null,
                    Collections.singleton(new SimpleGrantedAuthority(role))
            );
        }
        return null;
    }
}
